Strongyloidiasis is a neglected infectious disease with diverse clinical manifestations that may lead to severe complications, including death in immunocompromised individuals. Uncomplicated infections can be diagnosed early using serological testing. Regarding treatment, the World Health Organization recommends ivermectin, thiabendazole, and albendazole as effective therapies against Strongyloides stercoralis. The objective of this study was to evaluate the therapeutic effectiveness of ivermectin 200 μg/kg/day for 2 consecutive days in patients infected with S. stercoralis, with the aim of optimizing treatment efficacy while shortening the duration of therapy compared with longer regimens. This before-and-after study assessed the therapeutic effectiveness of ivermectin 200 μg/kg/day for 2 consecutive days in patients with S. stercoralis infection. From January to October 2023, 3,814 patients with suspected S. stercoralis infection—presenting with symptoms such as urticaria, abdominal pain, and loose stools with seropositivity on an enzyme-linked immunosorbent assay for IgG antibodies against S. stercoralis—were screened, and 42 patients with uncomplicated S. stercoralis mono-infection were recruited. Symptoms, IgG optical density antibody titers against S. stercoralis, and eosinophils were assessed before and after treatment. Therapeutic effectiveness was evaluated based on cure rate and disease reduction after intervention. After 3 months of treatment, the overall effectiveness of ivermectin 200 μg/kg/day for 2 consecutive days reached 95.2%, of which 50% were completely cured, 9.5% had symptom resolution without improvement in paraclinical indicators, 21.4% experienced clear symptom reduction, and 14.3% had symptom recurrence. The regimen of ivermectin 200 μg/kg/day for 2 consecutive days demonstrated high effectiveness in the treatment of strongyloidiasis.